The final arrangements are being put in place, and barring any last-minute hitches, Kate and Gerry McCann expect to meet the pontiff tomorrow.
Ms McCann is a devout Catholic and the couple have leaned heavily on their faith throughout the last three-and-a-half weeks, attending church regularly and visiting Portugal’s holiest shrine.
The couple will attend a general audience in Rome and it is hoped Pope Benedict XVI will refer to Madeleine during prayers in St Peter’s Square. The McCanns feel the trip will “help them spiritually”.
The visit will be the first of a number the couple are planning to make to countries including Spain, Germany and the Netherlands.
It is 26 days since Madeleine, now aged four, was taken from her bed as she slept in the family’s holiday apartment in Praia da Luz, on the Algarve.
This morning, the couple made their now routine trip to the nearby creche to drop off twins Sean and Amelie, while the details of their trip were arranged.
The McCanns received two offers of private jets, including one thought to have been offered by British tycoon Philip Green.
The McCanns yesterday visited the beach at Praia da Luz, to look at an 800-square-foot inflatable billboard of Madeleine’s face.
The poster was put up by two Glaswegians who work in advertising, and who drove from Scotland to the Algarve to help raise the profile of the case.
Ms McCann, wearing a brown skirt, white top and clutching her daughter’s favourite Cuddle Cat toy gazed at the huge poster the men have set up.
The couple held hands as they thanked Chris Lennox and Les Harley. Mr McCann described the billboard as “brilliant”.
He added that the couple were overwhelmed by all the support they have received.
“Some people are going to absolutely extraordinary lengths to help us. We would like to thank the thousands, if not millions of people who are helping,” he said.
“We thank them from the bottom of our hearts.”
Mr Lennox, 35, from Prestwick said he had a young family and wanted to do something to help.
“My heartstrings have been pulled on this and I want to help. I have a family with small kids and my wife has been following this from day one.
“She told me to come out here and do what I could.”
Mr Harley, from Irvin in Ayrshire added: “I am a family man, I have children and grandchildren.
“When I was given the opportunity to come down here I just jumped at the chance. The rest of the world has been watching this.”
The men will take the poster around the Algarve and set it up in prominent places to remind people of Madeleine.
Above the two large pictures of the little girl, there is information about the £1.5 million reward and contact telephone numbers.